Combined Effect of Substrate Temperature and Sputtering Power on Phase Evolution and Mechanical Properties of Ta Hard Coatings

Ta hard coatings were prepared on PCrNi1MoA steel substrates by direct current magnetron sputtering, and their growth and phase evolution could be controlled by adjusting the substrate temperature (T-sub) and sputtering power (P-spu) at various conditions (T-sub = 200-400 degrees C, P-spu = 100-175 W). The combined effect of T-sub and P-spu on the crystalline phase, surface morphology, and mechanical properties of the coatings was investigated. It was found that higher P-spu was required in order to obtain a-Ta coatings when the coatings are deposited at lower T-sub, and vice versa, because the deposition energy (controlled by T-sub and P-spu simultaneously) within a certain range was necessary. At the optimum T-sub with the corresponding P-spu of 200 degrees C-175 W, 300 degrees C-150 W, and 400 degrees C-100 W, respectively, the single-phased and homogeneous a-Ta coatings were obtained. Moreover, the a-Ta coating deposited at T-sub-P-spu of 400 degrees C-100 W showed a denser surface and a finer grain, and as a result exhibited higher hardness (9 GPa), better toughness, and larger adhesion (18.46 N).

Automated summary

Hard coatings were prepared on PCrNi1MoA steel substrates by direct current magnetron sputtering, and their growth and phase evolution were controlled by adjusting the substrate temperature (T-sub) and sputtering power (P-spu). The combined effect of T-sub and P-spu on the crystalline phase, surface morphology, and mechanical properties of the coatings was investigated. The optimized conditions resulted in the deposition of single-phased and homogeneous a-Ta coatings with improved hardness, toughness, and adhesion.